9.0

really awful
Typical Repair Cost:
No data
Average Mileage:
56,300 miles
Total Complaints:
2 complaints

Most common solutions:

  1. new engine (1 reports)
  2. suggest bulletin pip5762 (1 reports)
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problem #2

Jul 042025

Sierra 1500 AT4 6.2L

  • Automatic transmission
  • 66,000 miles

2020 GMC Sierra AT4 with the 6.2L engine. At 66,000 miles, the vehicle produced heavy grey smoke from the exhaust, and the dipstick showed no oil (500 miles since the last dealer oil change). I had it towed to the dealer, who diagnosed a completely failed engine requiring replacement due to severe piston scarring, allowing the oil to escape. Fortunately, I have an extended warranty, but GM will not cover a loaner/rental while I wait for the backordered replacement engine to be installed.

- Allan B., Raleigh, NC, US

problem #1

Sep 252022

Sierra 1500 Elevation 3L I6

  • Automatic transmission
  • 46,518 miles

Purchased truck certified used in 2022 with 43,292 miles. Immediatly made one 1,200 mile trip the following day and the check engine light came on along with warning for "reduced engine power." Limped to the nearest dealer and was told my oil was 4 quarts low! After being mocked about checking my oil, I reminded the dealer that I had just bought the truck. They told me oil consumption was normal; which this amount was not. The book indicates 1-2 quarts during the span of an oil change is normal.

It took over a year to convince the dealer this was a real problem after 4 more breakdowns and 2 oil consumption tests. Then I waited 3 months on parts. From what I gathered, this is only a problem with the diesel engines on 2020 Silverado and Sierra 1500s. The bulletin is: PIP5762

- Emily P., Saratoga Springs, UT, US